Furnace



Feb. 26, 1929. 1,703,776

A 5. TL NELSON FURNACE Filed Oct. 51, 1921 2 Sheets-Sheet 1 Feb. 26, 1929. 1,703,776

r s. T. NELSON I FURNACE 2 Sheets-Sheet 2 Filed Oct. 31, 192] Patented Feb. 26, 1929.

UNITED STATES PATENT OFFICE.

SVEN T. NELSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO SULLIVAN MACHINERY COM- 7 YANY, A CORPORATION OF MASSACHUSETTS.

FURNACE.

Application filed October 31, 1921. Serial No. 511,900.

My invention relates to furnaces, and more particularly to blank heating furnaces for heating blanks preliminary to forging operations.

An object of my invention is to provide an improved furnace. Another object of my invention is to provide an improved heating furnace for the heatin of continuous series of blanks for use in forging machines. A further object of my invention is to provide an improved heating furnace having means whereby blanks may be automatically fed through the furnace and discharged when heated to the desired temperature. Other objects and advantages of'my invention will hereinafter more fully appear.

In the accompanying drawings I have shown for purposes of illustration one form which my invention may assume in practlce.

In these drawings,

Fig. 1 is a plan view, partially broken away, of the illustrative form of my improved furnace.

Fig. 2 is a front elevation thereof.

Fig. 3 is a vertical section on a plane corresponding to the line 33 of Fig. 2.

Fig. 4 is a series of views showing the furnace charging device.

It is now a well known fact that the cutter bits employed with cutter chains of coal mining machines, may be advantageously and cheaply made up by automatic forging machines. It is also common to other manufacturing processes to forge shapes from heated blanks. For the purpose of providing these heated blanks continuously and at suitable intervals for their most advantageous treatment, I have devised the invention whose illustrative form I nowdescribe.

comprises a heating furnace generally designated 1 and automatic blank discharging means generally designated 2. The

furnace 1 together with the blank discharging means 2 is mounted upon a suitable frame generally indicated by 3 having side. This housing is lined on the top, bot-.

tom, sides and back with fire brick, all joints bein luted with fire clay. In the front wall of t. e furnace there are arranged one r In its illustrative form my invention more oil burners, three of these being shown 1n the present drawings and designated 6, although it will be obvious that depending upon the number of the bits to be heated and the time which may be devoted to the heating of the bits, there may be a wide va- 1111131011111 the number of burners necessary.

Spaced between the burners 6 within the casing of the furnace and projectin from the front wall 7 thereof are a series 0 guide ribs 8 which are spaced apart by short distances in such manner as to provide guide ways for the blanks to be heated, while wider spaces separate the several guideways, and through these wider spaces the burners discharge and the remaining space is filled up with fire brick or fire clay as indicated at 9 to protect the guide ribs 8 and the front wall of the furnace. Arran ed in the top of the furnace are a series 0 feed slots 10, 11, 12 and 13, which slots are in alinement with the channels formed between the ides 8 in which the blanks are to be guide during heating. As illustrated in Fig. 3, bits dropped in through the feeding slots remain superimposed one upon another between the guides 8 and are gradually fed down on operation of the discharging means by gravity as later described. It Wlll also be evident that one or more stacks of blanks herein in the form of bits may be provided in the furnace and that the furnace may be designed to accommodate as many stacks as desired. Herein it will be noted from'Fig. 1 that the blanks are in part protected by the guides from the direct heat of the combustion chamber, and as a result only the projecting portions, which will be the portions to be worked, will be heated up to the highest temperature.

For the purpose of permitting the loading of the furnace for the first time I employ a magazine member 17 which is U-shaped in cross section except at the bottom Where it is rectangular as indicated at 18. Across the bottom of this member lies a pin 19 having a hooked end 20 which may be enga ed by means inserted through any of the ischarge slots 21, later described, arranged below and in alinement with the bottoms of the stacks of bits. The magazine member 17 is filled with blanks and is then inserted through one of the charging slots 10, 11, 12 or 13. When this magazine member is resting upon the bottom of the furnace opposite one of the discharge slots 21 which are pro- Vided in the front wall, the pin 20 may be withdrawn and the bits will then completely fill one of the guideways between the members 8. Thereafter the magazine member 17 is withdrawn and, during the operation of the furnace, bits are fed into the va rious feed slots as rapidly as they are discharged through the discharge slots 21.

The bottom of the furnace is provided with a water jacket 22 and in the upper surface of the water jacket, i. e. in the bot tom plate of the furnace there are formed guideways 23 in which are reciprocable plungers or" ejectors 24: each adapted to engage the bottom bit in its respective stack and force it out through the respective discharge opening 21. These rods are reciprocated by pitmans 25 pivoted to crank disks 26 and rotatable by means of shafts 27 driven by gears 28 in bearings 29. A common driving shaft 30 having pinions 31 thereon drives the gears 28 and consequently the period between the discharge of blanks from the several stacks may be made uniform and may be adjusted as desired by varying the rate at which the shaft 30 rotates. It will be observed that the rods '24, being surrounded on three sides by water cooled Walls, are prevented from overheating and thatthe direct access of heat from the furnace to their upper sides is prevented by the lining of fire brick on the bottom of-the furnace.

From the foregoing description the mode of'operation of this improved bit heating mechanism will already be apparent. Let it be assumed that the several stacks of bits are already in position and that the furnace has been heated up to the desired temperature and the bits likewise brought to the temperature which is desired. Then by driving the shaft 30 by means of the pulley shown thereon it will be possible successivel-y to discharge these blanks and if unheated blanks are continuously supplied through the slots 10, etc., as blanks are discharged heated through the discharge openings 21, the operation of the furnace will evidently be continuous. It will be understood that either oil fuel or gas of any description can be used with the furnace and that the mechanism may be operated by an electric motor or in any other suitable way provided adjustment of the timing is made possible. It will also be noted that the furnace heating chamber is open only through the two flues 32 at the top thereof and so that the heat is concentrated in a very efficient manner.

WVhile I have in this .application -specifically described one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that .means in said chamber to receive and guide a series of blanks during their passage through the chamber, said guides having surfaces contacting with said blanks to cover a substantial portion of said blanks but to have the portions to be worked projecting into the chamber whereby the pertions of the blanks to be worked may be heated to a much higher temperature than the protected portions, and means for serially discharging the blanks.

2. In a blank heating furnace, a heating chamber, parallel blank guides formed therein each being adapted to receive a stack of superimposed blanks, means to feed the blanks in said guides through openings formed in the top of said chamber, and means including reciprocating rams movable in a plane perpendicular :to said guides to successively engage and eject the lowermost blanks of each stack individually from said chamber in a predetermined timed relation.

3. In a blank heating furnace, a combustion chamber provided with an inclined surface and a burner, means to guide a series of blanks along said inclined surface arranged and contacting with the body portions of said blanks to allow the same to have only their. portions to be worked exposed to :the flame of said burner, and means for automatically successively engaging .and discharging the blank of highest temperature from said guiding means.

4:. In a blank heating furnace, a combustion chamber, means for guiding a series of blanks through said chamber, said means having surfaces contacting with said blanks to cover a substantial portion thereof but to have the portions to be worked projecting into said chamber, and power operated means for discharging the blanks from said chamber. v

5. In a blank heatiIlgfu-rnace, a combustion chamber, spaced inclined blank guides formed thereineach being adapted to receive a stack of blanks, burners disposed between said guides and discharging in a direction away therefrom, said blanks being exposed to direct radiation in said combustion chamber, and means to automatically engageand discharge the blanks individually from said chamber.

6. A blank heating furnace comprising a heating chamber, means for feeding a stack of superimposed blanks thereto by gravity, and means for successively engaging and having surfaces contacting with said blanks to cover a substantial portion thereof and have only the portions to be worked projecting into said chamber, and means for successively engaging and discharging the blanks individually from said stack.

8. In a blank heating furnace, a heating chamber, means for guiding a series of blanks through said chamber, said means having surfaces contacting with said blanks to cover a substantial portion thereof and have only the portions to be Worked projecting into said chamber, and means comprising a reciprocable plunger engageable with certain of the blanks to individuall eject the same which have been longest subjected to the heat of said chamber therefrom.

9. A blank heating furnace comprising a heating chamber adapted to receive a series of blanks, means for individually ejecting the blanks from said chamber comprising a reciprocable plunger engageable with certain of the same, and means for feeding a stack of superimposed blanks to said ejecting means by gravity, said latter means comprising an inclined blank receiving guide way disposed substantially perpendicular to the line of reciprocation of said plunger.

In testimony whereof I alfix my signature.

SVEN T. NELSON. 

